Fiberglass comes in many shapes and sizes and can be used for a variety of applications. A general discussion of glass fiber technology is provided in "Fiberglass" by J. Gilbert Mohr and William P. Rowe, Van Nostrand Reinhold Co., New York, 1978, which is hereby incorporated by reference. Water soluble phenolformaldehyde resins such as resoles have been known for a number of years. See, for example, U.S. Pat. Nos. 4,060,504, 4,757,108 and 4,960,826, hereby incorporated by reference.
A number of references disclose mats that are comprised of short siliceous materials such as chopped glass fiber from a continuous filament glass fibers. These fibers are extremely short in length, namely one-half inch and less. The glass materials may also be obtained by chopping other glass fibers to obtain short length siliceous materials. U.S. Pat. No. 2,723,209 describes such mats utilizing a binder formulation of acrylonitrile-butadiene copolymer. To this is added a phenolic resin solution which is then further diluted with water so that the solids content is approximately 2%. A small amount of this mixture is sprayed onto a glass fiber mat and an excessive amount is later poured onto a roller over which the wetted mat travels. The impregnated mat then passes over concentrated heat of direct fired or radiant burners and then into a baking oven at a temperature of 250.degree. to 400.degree. F. for 10 to 25 minutes. The mat with the resin material thereon is fully cured. Mats comprised of a bed of glass fibers are to be treated as a sheet so that it can be impregnated. Utilization of resinous materials for such compositions are primarily for complete support of the overall structure. This technique is sharply contrasted with the present invention which is concerned with binders that are to be applied to glass fibers after the fiber is formed by different techniques.
Another glass fiber mat reference is U.S. Pat. No. 4,006,272 which pertains to a process for preparing resin impregnated glass fiber mats in which the binder resin has a high rate of dissolution in vinyl monomers. The binder resin is a styrene resin or copolymer composed mainly of styrene. Blended with the styrene may also be unsaturated polyester resin having a melting point of 80.degree. to 130.degree. C.
U.S. Pat. No. 4,258,098 pertains to a glass fiber mat which utilizes a urea formaldehyde resin together with styrene butadiene latex copolymer further containing 0.1 to 5% by weight acrylamide, methacrylamide, N-methylolacrylamide or N-methylolmethacrylamide. Another glass fiber mat document is U.S. Pat. No. 4,560,612 which has a binder composition of urea formaldehyde, styrene-butadiene latex copolymer and a fully methylated melamine-formaldehyde copolymer.
Another glass fiber mat is disclosed in U.S. Pat. No. 4,849,281 where the mat has a particular unique blend of glass fibers such as wool fibers and textile glass fibers together with melamine cross-linked styrene butadiene resin.
U.S. Pat. No. 4,892,695 discloses a fiber glass mat containing glass fibers, polyolefin fibers and polyamide fibers together with a latex binder such as styrene-butadiene latex.
U.S. Pat. No. 3,914,192 discloses for use as reinforcement for elastomeric materials a plurality of glass fibers, a thin film coating on the surface of the glass fibers and an impregnant in the bundle, the impregnant comprising a blend of resorcinol aldehyde resin and an elastomer.
It is an object of the present invention to have an improved glass fiber binding composition utilizing the combination of aqueous latex and a thermosetting composition. The binder coats the entire fiber as well as the juncture points. In the prior art, binders with a formaldehyde thermosetting composition are designed to coat and/or migrate to the glass fiber juncture points not to coat individual fibers.
It is an object of the present invention to obtain glass fiber compositions of improved handleability and reduced fiber "fallout" in the use of the glass fiber compositions. Prior to the present invention, handlers of fibrous glass products vigorously complained about the handleability and skin irritation they receive.
It is an object of the present invention to obtain glass fiber compositions in their fully cured state that have low odor associated with such cured glass fiber compositions.